Pluggable unit



March 14, 1961 R. R. cARDAsclA ETAL 2,975,390

PLUGGABLE UNIT Filed DSO. 51, 1958 4 Sheets-Sheet 2 March 14, 1961 R. R.cARDAsclA ETAL 2,975,390

PLUGGABLE UNIT Filed Dec. 31, 1958 4 sheets-sheet s 72 @N/ff March 14,1961 R. R. cARDAsclA ETAL 2,975,390

PLUGGABLE UNIT Filed Dec. 5l. 1958 4 Sheets-Sheet 4 United States PatentO PLUGGABLE UNIT Rinaldo R. Cardascia, Wappingers Falls, and Ralph D.Markle, Jr., Red Hook, N.Y., assignors to International BusinessMachines Corporation, New York, N.Y., a corporation of New York FiledDec. 31, 1958, Ser. No. 784,130

10 Claims. (Cl. 339-45) This invention relates to electrical connectiondevices and more particularly to a pluggable connector device of thetype adapted to complete a multiplicity of circuits substantiallysimultaneously.

Such multiple connector devices are finding an increasing number ofapplications as electrical and control circuitry become larger and morecomplex. Certain problems, however, accompany this increasing size andcomplexity and particular difficulties have been encountered inpluggable connector devices adapted to connect a large number ofcircuits. Each contact is completed by Sliding a male connector memberinto a cooperating female connector member. In conventional pluggableunits a substantial frictional force is provided between the two membersto provide a suitable contact of low electrical resistance between thecooperating members and to provide a wiping action of suicient magnitudeto remove any surface oxide film on those members. Where the number ofconnections is in the order of one hundred or more thetotal forcerequired to suitably connect the pluggable unit is of substantialmagnitude and mechanical devices, such as screw jacks, have beenresorted to. However, when even larger numbers of contacts are providedin individual pluggable units, as is frequently desirable in digitalcomputer equipment for example, the resultant forces are of such amagnitude that even the best mechanical devices are not completelysuitable.

Accordingly, it is an object of this invention to provide an improvedelectrical contact structure suitable for use with large pluggableunits.

Another object of the invention is to provide a pluggable unit contactoperating mechanism which is actuated by uid means and which permits theeasy insertion and removal of large pluggable units from theircooperating receptacles.

Still another object of the invention is to provide an improvedpluggable unit structure in which the problem of alignment betweencooperating sets of contacts is minimal.

The invention provides a pluggable unit connector device which has amultiplicity of male contacts and a cooperating receptacle carryingfemale contacts which are initially open so that they offer little or noresistance to the insertion to the pluggable unit. Associated with thereceptacle is a fiuid actuated means which operates the female contactmembers to close them firmly against the male contacts in a wipingaction after the unit has been locked in position. As the femalecontacts are open initially, the alignment of the male contact portionsrelative thereto is no longer a critical problem. A fluid operatedejection means is provided which, after the release of the liuidpressure on the female members, acts to unlock the removable pluggableunit and to move it away from the receptacle such that there isclearance between the cooperating sets of contacts. A structureembodying the principles of the invention has been employed inconjunction with a digital computer pluggable Patented Mar. 14, 1961unit which has six hundred contacts of the knife type mounted in an areaof approximately one-eighth square foot. If the conventional type ofpluggable unit contact structure had been utilized, a force of about onethousand pounds would be required to insert and to remove the unit. Theunit, according to the invention, is compact and easily operated, andhas exceptionally good mechanical and electrical reliability.

Other objects and advantages of the invention will be seen as thefollowing description of a preferred embodiment progresses, inconjunction with the drawings, in which:

Fig. l is a side view of a portion of the pluggable unit structure andcooperating receptacle which incorporates principles of the invention;

Fig. 2 is an end view, in partial section, taken along the line 2 2 ofFig. l;

Fig. 3 is a top view of the structure taken along the line 3-3 of Fig.l;

Fig. 4 is a view similar to that of Fig. 3 with the pluggable unitcontacts separated from the cooperating receptacle contacts;

Fig. 5 is a sectional view of the cooperating contacts taken along theline 5-5 of Fig. l;

Fig. 6 is a sectional view corresponding to that of Fig. 5 in whichfluid pressure has been applied to the female contacts;

Fig. 7 is a perspective view of the fixed and movable contact elements;

Fig. 8 is an elevational view of the contact structure of the receptacletaken along the line 8 8 of Fig. l;

Fig. 9 is a view of the lluid control system associated with theapparatus of Fig. l; and

Fig. 10 is a sectional view of a portion of the locking and ejectionapparatus, taken along the line 10-10 of Fig. 9.

A preferred embodiment of the invention includes a fixed frame structuredesigned to receive several pluggable units which are positioned inthree horizontal rows. Each pluggable unit carries one hundredencapsulated units of one or more circuits secured to a frame with theirleads connected via a terminal block to six hundred male contact membersarranged in eight columns of seventy-tive contacts each. The fixed framecarries a terminal block which has a similar number of female contactmembers correspondingly arranged. These members are initially spacedapart to facilitate the proper positioning of the pluggable unitrelative thereto. After the pluggable unit is locked in place, airpressure is applied via a control valve and bladder arrangement to forcethe fixed contact members into firm engagement with the movable members,thus providing excellent electrical connections.

When it is desired to remove the pluggable unit, the control valve isoperated to release the air pressure on `the bladder and simultaneouslyto operate an ejector mechanism which unlocks the unit and forces itoutwardly away from the fixed terminal block. The entire pluggable unitmay then be easily removed from the frame by hand.

A detailed understanding of this preferred embodiment of the inventionmay be obtained with reference to the drawings. In Figs. l and 2 thereare shown two views of the fixed frame structure 10 which is adapted toreceive a plurality of pluggable units 12, one of which is shown. Aseach of the receptacles in the frame and the cooperating pluggable unitis similar, only one will be shown and described.

The pluggable unit 12 includes a frame 14 adapted to carry one hundredencapsulated units of one or more circuits 16 (see Fig. 3). These arelogical circuits suitable for use in a digital computer, for example,and are supported by suitable fastening means (not show-n) from theapertured frame tongues 18. A terminal block 20, of suitable insulatingmaterial such as molded melamine, which contains six hundred knife typecontact members 22 is positioned rearwardly of and bolted to thecircuitry supporting frame 14. Terminals 24 associated with thosecontacts are brought out to the side of the terminal block as shown inFigs. 3 and 4, and connections may be made thereto, as required, byconventional means such as wire wrapping. A cover plate 26 is providedwhich is fastened over those terminals.

The fixed frame includes upper and lower structural members 28 and 30which extend forwardly and define an aperture to receive the pluggableunit. Each member has a channel 32 adapted to receive a cooperating rail34 posi-- tioned on the movable pluggable unit 12.

Mounted in the rear of each receptacle portion of the frame is aninsulating terminal block generally indicated at 36 in which arepositioned six hundred female contact 'members which cooperate withcorresponding contacts 22.

Each of these contact members has a contact portion 38 positioned withinthe terminal block and a terminal portion 40 which extends rearwardly ofthe terminal block and to which a suitable connection may be made byconventional means.

Mounted on the terminal block 36 is a control valve 42 which has twosolenoid actuators 44 and 46 associated therewith (Fig. 1). This valvecontrols the flow of air from a supply (not shown) through line 48 tolines 50 and 52. Positioned at the top and bottom of each receptacle arepluggable unit ejector mechanism cylinders 54 and 56 which are connectedto line 50 via lines 58 and 60 respectively. The ejector mechanisms actto unlock the pluggable unit and to force it way from the xed connectorsin a manner hereinafter described in detail. Line 52 is connected to achamber 62 associated with the female contact operating mechanism.

The fixed contact member is a flat metal strip of uniform width which isfolded upon itself at the terminal end of the member to provide a twoply member having a terminal portion 40 where the two plies contact eachother and a contact portion 38 where the two plies are spaced apart asshown in Figs. -7. Each ply in the contact portion 38 includes a lip 64,and a dat portion 66 substantially parallel to and coextensive with thecorresponding portion of the other ply. The connector has its point ofnarrowest width adjacent the lips 64 which spread outwardly from thatpoint to provide an access aperture for entrance of the cooperatingmovable contact member 22. That member is a flat knife type of contactand is formed with its terminal portion 24 from a single thickness ofmetal. The fixed contact may be manufactured from beryllium copper andthe knife contact from Phosphor bronze, for example.

The fixed female contact members are mounted within the terminal block36 which has two end walls 68, 70 and two apertured side walls 72, 74(Figs. 5-6). The terminal portion 40 passes through walls 72 whoseapertures are designed to conform to the transition portion between theterminal portion and the parallel Contact portions 66. The lip portions64 pass through apertures in the opposite wall 74. Disposed outside ofthe flat portions and in contact therewith are thin fiat sheets 76 offlexible acrylite and interposed between the sheets are inliatablebladders 78 which are positioned between the columns of contacts and areconnected at one end to the chamber 62 and at the other end to a blindchamber as shown in Fig. 8. The llat sheets 76 provide an evendistribution of pressure when the bladders are inated and additionallyprovide a degree of protection to the bladders against damage, fromsharp contact edges for example.

In operation, the pluggable unit 12 is inserted into its cooperatingreceptacle with the rails 34 positioned in the channels 32 such thataccurate alignment of the male contacts 22 with the cooperating femalecontacts 38 is assured. As the male contacts 22 are inserted into thefemale contacts 38, the lip portions 64 of latter are spaced apart sothat there is negligible friction between the two sets of contactmembers. Additionally, the outwardly angled lips guide the knife bladecontacts 22 so that absolute alignment of the two types of contacts witheach other is not essential. This permits the pluggable unit to bequickly and easily inserted in a manual operation in sharp contarst withconventional types of pluggable units having fewer connections whichdemand critical alignment and require complex mechanical insertionassistance. When the pluggable unit is properly positioned, it is lockedin place by mechanical means and the control valve 42 is actuated by thesolenoid 46 to supply air pressure via line 56 to the female contactactuating mechanism which operates to inate the bladders 78 and closethe female contacts 38 on the cooperating male contacts in a wipingaction, particularly adjacent the lip portions, which are forcedforwardly and remove any oxide film that may have formed, therebyachieving suitable contacts of low electrical resistivity.

The control valve 42 is shown in section in Fig. 9. It includes a casing80 having an inlet line port 82 and two control ports 84 and 86. Twovalve members 88 and 90 are housed within the valve casing. Each valvemember includes a valve head which carries an O-ring sealing member anda valve stem which is connected to the associated solenoid 44 and 46respectively. The valves are connected together by a lost motionconnection 92 which comprises a T member attached to the valve whichslides in a slotted hook member attached to the valve 88.

When a pluggable unit is not positioned in energizable condition in thereceptacle the valve members are in the position as shown in Fig. 9. Inthat circumstance both line 50 and line 52 are connected to theatmosphere through discharge ports formed bythe open ends of the valvecasing cylinder. After a pluggable unit has been inserted into thereceptacle frame, solenoid 46 is energized and moves the valve 90 in adownward direction as shown in Fig. 7, thereby connecting the air inletline 48 with line 52 through ports 82 and 86, and applying air pressureto the chamber 62 to inate the bladders 78, thereby closing the femalecontacts on the cooperating male contacts. The lost motion connection 92permit valve member 90 to move independently of valve member 88 in thismanner. The valve remains in this position until solenoid 44 isenergized.

When it is desired to remove the pluggable unit from the frame, thesolenoid 44 is energized. This energization may be initiated manually asby pressing a push button or automatically as a result of an errorsignal generated by the associated equipment upon detection of a faultin the connected pluggable unit. When the solenoid 44 is energized, thevalve member 88 is moved upwardly and through the lost motion connection92, the valve member 90 simultaneously is carried from its lowerposition upwardly back to the position shown in Fig. 7. This operationdisconnects line 52 from the air supply (connecting it to `theassociated discharge port and permitting deflation of the bladders) andsimultaneously connect line 50 to the air supply via line 48 and ports82 and 84. Air pressure thus is supplied through lines 58 and 60 to thepluggable unit ejector mechanisms 54 and S6. The ejector mechanismsoperate to unlock the pluggable unit and move it outwardly from thefixed terminal block 36, to the position as indicated in Fig. 4. In thatposition the male contacts 22 are completely clear of the femalecontacts 38. Upon de-energization of the solenoid 44 the valve member 88is returned to the position of Fig. 7 by spring biasing means (notshown).

The operation of the unlocking and ejector mechanism may be understoodwith reference to Figs. 9 and 10. The rail 34 on the pluggable unitframe 14 is terminated short of the rear end of the pluggable unit frameand a block 94 having the same width as the rail 34 is aligned with butspaced from the rail and attached to the frame by bolts 96. PositionedWithin a cylindrical passageway in this block is a plunger mechanism 98.The plunger mechanism includes a rod having a head portion 100 and areduced shank portion 102 which passes through a wall of the block. Across member 104 having a pair of rollers 106 and 108 mounted thereon ispinned to the forward end of the shank 102. A spring 109, positioned onthe shank 102, acts against the head 100 to hold the cross member 104 incontact with the block.

Positioned on either side of the channels 32 in the fixed frame members30 adjacent the rear end thereof are locking arms 110 and 112 which areadapted to pivot about pins 114 and 116 respectively and which arebiased inwardly toward the center of the channel by springs 118 and 120respectively. As the pluggable unit is moved inward towards the fixedterminal block 36, the leading surface of the block 94 contacts thelocking arms 110 and 112 and cams them outwardly to permit the block tomove past. After it has moved past the springs 118 and 120 pivot thelocking arms back to the position shown in Fig. so that their stopsurfaces 122 and 124 respectively pivot in front of block 94 locking theunit in place with the two groups of contact members properly positionedand preventing manual removal of the pluggable unit.

Each ejector mechanism includes a cylinder 126 in which is mounted apiston 128 which is connected to a piston rod 130, the end of which isadapted to contact the plunger 98. When the control valve is operated toapply air pressure through line 60 to the ejector cylinder 126 thepiston rod 130 is forced forward thereby moving the plunger 98 forwardand compressing spring 109. The initial movement of the plunger movesthe cross bar 104 and associated rollers 106 and 108 to cam the lockingarms 110 and 112 apart, thereby permitting movement of block 94 and thepluggable unit frame. Further forward movement of the piston rod 130drives the block and the pluggable unit outwardly away from the fixedcontact terminal block, thereby separating the male and the femalecontacts as shown in Fig. 4. As the air pressure on the bladder has beenrelieved by this time (through the coordinated operation of the controlvalve 42), the pluggable unit moves freely and only a moderate amount offorce is required to move the plug gable unit the necessary distanceoutwardly. The unit that has been ejected is clearly indicated as itprotrudes a short but easily noticed distance from the fixed framestructure, and it may thereafter be completely removed by hand.

Thus it will be seen that the invention provides an improved pluggableunit system whereby the connection and disconnection of pluggable unitconnection devices is greatly facilitated. The system providescoordinated operation of pneumatically controlled electrical contactsand pluggable unit locking and ejection mechanisms. Devices constructedaccording to principles of the invention may have several hundred pairsof cooperating contacts and each unit may be inserted and removed from acooperating receptacle by hand in contrast with pluggable unit systemsutilizing conventional types of connector components which requirecomplex jacking mechanisms to overcome the tremendous frictional forcesassociated therewith. While a preferred embodiment of the invention hasbeen shown and described herein it will be understood that the inventionis not intended to be limited thereto or to details thereof anddepartures may be made therefrom within the spirit and scope of theinvention as defined in the following claims.

We claim:

1. A pluggable unit assembly adapted simultaneously to complete amultiplicity of electrical circuits comprising a fixed receptacle havinga group of female contact members mounted therein, `a movable unithaving a group of male contact members, said female contact membershaving contact portions normally spaced apart to receive correspondingmale contact portions, fluid operated means including inflatablebladders disposed adjacent said contact portions on either side thereofand adapted to be inated to urge said contact portions toward oneanother and into engagement with corresponding male contacts when saidmale contacts are positioned therebetween, fluid operated pluggable unitejection means adapted to slide said movable unit so that said malecontacts move away from said female contacts including control meansadapted simultaneously to deflate said bladders to release said contactsand to operate said ejection means to slide said movable unit outwardlyrelative to said rcceptacle.

2. An electrical connector assembly of the pluggable unit typecomprising a receptacle having `a group of female contact membersmounted therein aligned in a plurality of rows, each of said contactmembers having two coextensive parallel spaced contact portions, apluggable unit having a group of male contact members adapted to coactwith said group of female contact members, each of said male contactmembers being adapted to be inserted between said spaced portions of acorresponding female contact member, and pressure applying meanscomprising an inflatable bladder disposed outwardly of said spacedportions of each row of said female contact members, a flat flexibleinsulating sheet positioned between each bladder and the associatedcontact portions and control means adapted to inflate said bladders tourge said portions toward one another in a wiping action with said malecontact members whereby electrical oonnections of low resistivity areobtained between corresponding members of said groups.

3. The apparatus as claimed in claim 2 and further including a pressureoperated ejector mechanism associated with said receptacle and adaptedto be operated to move said group of male contacts away from said groupof female contacts.

4. The apparatus as claimed in claim 3 and further including controlmeans adapted to release said pressure applying means and to operatesaid ejection mechanism substantially simultaneously in a coordinatedoperation.

5. An electrical connector assembly of the pluggable unit typecomprising a fixed receptacle having a group of female contact membersaligned in a plurality of rows and columns and mounted in a terminalblock structure, each of said contact members having two coextensiveoppositely disposed contact portions, a movable pluggable unit adaptedto be inserted into said receptacle and locked therein, said pluggableunit having a group of male contacts correspondingly aligned and adaptedto coact with said group of female contacts, each of said male contactmembers being adapted to be inserted between the opposed portions of acorresponding female contact member, flexible sheet members disposedbetween the columns of female contacts within the terminal block oneither side of said opposed portions, an infiatable bladder positionedbetween each pair of said sheet members, said bladders being adapted tourge said portions towards one another into firm engagement withassociated male contact members when inflated, a source of uid pressure,and a control valve adapted to connect said source to said bladders toinliate the latter, whereby electrical connections of low resistivityare obtained between corresponding contact members of said groups.

6. The electrical connector assembly as claimed in claim 5 and furtherincluding a pressure operated ejector mechanism associated with saidfixed receptacle, a second control valve adapted to apply pressure fromsaid source to said ejector mechanism, said ejector mechanism beingadapted when activated to unlock said pluggable unit and move itrelative to said receptacle such that said male contacts are spaced fromsaid female contacts, said second control valve being adaptedsubstantially simultaneously to release the pressure on said bladder,thereby permitting said opposed contact portions to move apart and toconnect said ejector mechanism to said source to permit removal of saidpluggable unit from said receptacle.

7. A compact pluggable electrical contact unit assembly including areceptacle and a cooperating pluggable unit adapted to be easilyinserted into and removed from said receptacle, said pluggable unitincluding a multiplicity of ilat blade contact elements aligned in aplurality of rows and said receptacle having corresponding cooperatingcontacts, each said cooperating contact comprising two coextensivemembers having spaced apart, substantially parallel portions whichdefine a space therebetween, an insulating plate disposed to the outsideof each row of said contact members from said space and an inatablebladder associated with each row of Contact portions and disposedadjacent each plate, said pluggable unit being adapted to be positionedin said receptacle so that the blades are inserted between thecooperating contact members, a source of iluid pressure, and valve meansadapted to apply fluid pressure from said source to said bladders toinate them so that said contact members are urged toward one anotheragainst said blades in a wiping action to complete electrical circuitsbetween said blade contacts and the cooperating receptacle contactmembers.

8. The apparatus as claimed in claim 7 and further including mechanicallocking means disposed in said receptacle adapted to prevent manualremoval of said pluggable unit when said contact blades are positionedbetween said receptacle contact portions and a uid pressure controlmeans adapted to deilate said bladder to release the pressure on saidblades, to unlock said mechanical means, and to move the pluggable unitso that the blades are moved outwardly relative to said cooperatingcontact portions whereby the entire pluggable unit may then be manuallywithdrawn from the cooperating receptacle with case.

9. A control system for a pluggable electrical contact unit assemblyhaving a receptacle and a cooperating pluggable unit adapted to bepositioned in said receptacle,

said receptacle having a multiplicity of contacts aligned in a pluralityof rows, each said contact having two substantially parallel spacedportions defining a space therebetween, an insulating plate disposedagainst each said portion on the side thereof opposite said space andextending the length of the row, and inatable tubes positioned betweensaid rows of contacts, said pluggable unit having cooperating contactmembers adapted to be aligned in said receptacle with said cooperatingcontact member positioned between said contact portions, said controlsystem including rst means to inate said tubes when said pluggable unitcontact members are positioned in said space to force said contactportions towards one another to provide rm electrical contact betweensaid contact portions and said cooperating contact members and secondmeans operative substantially simultaneous to deate said tubes, therebyreducing the pressure of said contact portions on said cooperatingcontact members, and to move said pluggable unit outwardly of saidreceptacle so that said cooperating contact members are moved relativeto said contact portions.

10. The system as claimed in claim 9 further including a source of fluidpressure, and a control valve mechanism, wherein said first means isadapted to actuate said control valve mechanism to apply uid pressurefrom said source to inate said bladders and said second means is adaptedto actuate said control valve mechanism to deflate said bladders andforce said pluggable unit outwardly of said receptacle.

References Cited in the file of this patent UNITED STATES PATENTS1,501,157 Woernley July 15, 1924 2,636,068 Perkins Apr. 21, 19532,654,872 Saul et al. Oct. 6, 1953 2,673,227 Hubert Mar. 23, 19542,685,071 McCreary July 27, 1954 2,757,225 Dunn July 31, 1956 2,827,312Spencer Mar. 18, 1858 2,852,463 Gutzmer Sept. 16, 1958 2,881,404 KammApr. 7, 1959 2,883,638 Mark Apr. 2l, 1959

